The invention pertains to metal working, and specifically to devices for drilling or boring holes, thereafter called devices for making holes.
Known are devices for making holes (SU 1063543 A, Dec. 30, 1983; SU 1313586 A1, May 30, 1987; RU 2090315 Ca, Sep. 20, 2007) that have cutter heads and mechanisms by means of which a cutter is set to a specified dimension. In said devices, the specified dimension is set before making a hole, and is not corrected during the hole-making process. Also, the tool deviating from the hole axis is not corrected because it is not possible to control the hole axis while making a hole.
Also known is a device for making holes (RU 44072 U1, Feb. 2, 2005) comprising a cutter head with a device for moving a cutter in a radial direction from the drive whose control circuit input is connected via a converter to a computer numeric control (CNC) system output. The device makes it possible to change a hole size and shape while making a hole according to a preset CNC program by moving the cutter in a radial direction. Motion from the drive to the cutter is transmitted via a rod that passes inside a bar cavity. The rod is longer than the depth of drilling.
In terms of the combination of essential features and the achieved result, the device of patent RU 44072 C1 is the closest to the claimed device and is designated as the prototype.
The device's disadvantage is that during the hole making process the cutter head axis runs off the axis of the specified hole. It is then impossible to determine the runoff amount, let alone to correct it. The link of the cutter movement drive to, the cutter itself via a long rod contributes to increasing the runoff because the rod is insufficient rigid.